Control system for radioreceivers



Feb. 11, 1930. B. WASHINGTON ET AL 6,

CONTROL SYSTEM FOR RADIORECEIVERS Filed June 25, 1927 2 Sheets-Sheet. 1

Feia. 11, 193.0. B. wAs'HlfieToN ET AL 1,746,690

CONTROL SYSTEM FOR 'RADIORECEIVERS Filed June 25, 1927 2 Sheets-Sheet 2;

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IN ENTORS fio wden mskiiyow Patented Feb. 11, 1930' .um'rsn STATES. PATENT OFFICE BOWDEN WASHINGTON, OF NEW YORK, AND WILSON AULL, JR, OF ASTORIA, NEW YORK, ASSIGNORS TO REMOTROLE CORPORATION, A. CORPORATION OF NEW YORK CONTROL SYSTEM FOR RADIOBECEIVEBS Application filed 11111525, 1927. Serial No. 201,393.

Another object is to provide a simple single control arrangement for ,multi-stage so-called vacuum tube or electron relay amplification Another object is to provide a high power receiver of single frequency response which can be made to respond to a wide band of frequencies by means of a control station having a single frequency-control element located at any convenient point and may also have its out-put amplitude controlled at ornear the same point.

By means of our invention practically any modern radio receiver from the high frequency amateur type to the low frequency Navy type may be converted to take, for instance, the broadcast frequency band, or any other band, and'control it from a distance without intervening physical means, such as wires, cables, etc. f

In our invention the signal is picked up by a portable control box which may preferably contain a tunable regenerative detector having a coil, loop or capacity input. The outputof this detector is associated with the input of a stage of audio frequency amplification. The output of the latter serves to modulate an oscillator having a fixed frequency output. This oscillator has in its outputcircuit coupling means which may be either electro-static or electro-magnetic, said coupling means coacting with other coupling means associated with the input of a frequency changer whose output is in turn associated with the input of a receiver tuned to a chosen wavelength or with a fixed frequency receiver designed especially to coact with the other units of our invention. The system is susceptible-of embodiment in various ways for different pur oses.

Referringto t e drawings: Fig. 1 is a diagrammatic drawing of the system as a whole. 4 j,

control as indicated by Fig. 2 is a schematic wiring diagram of one form of frequency changer.

Fig. 3 is a schematic wiring diagram of one form of control unit.

Fig. 4 is a schematic wiring diagram of 5 another form of frequency changer.

The control box 10 has a signal pick-up coil or loopll, a frequency adjuster 12, a

gain control 13 and an output loop 14. The

frequency changer 15 has an input pick-up loop 16 and is connectedto the receiver 17 which has an output device 18.

In operation the coil antenna 11 and its associated circuit is adjusted by the condenser ,12 to be resonant with the frequency it is desired to receive. Associated with this circuit is the regenerative detector 20 with its regeneration control 21. The audio frequency output of the detector 20 by means of the vacuum tube 22 and the transformer 23 is further amplified and serves in any suitable manner to modulate the oscillator 24 having an output device 14. The frequency of this oscillator 24 may be permanently adjusted by the adjustable condenser 25. The amplitude of the modulation of the oscillator 24 may be varied by adjusting the plate voltage of the amplifier 22 by means of the high variable resistance 26 and by varying the sensitivity of the detector 20 by means of the adjustable feed back control 21. For convenience it may be preferable to operate these two adjustments by means of one manual the dotted line 13; Fig. 3, and the single knob 13, Fig. 1.

If a frequency changer of the type shown in Fig. 2 is used the further operation of the system is as follows:

Let us assume that the receiver 17 is either built or adjusted to respond to 530 kilocycles. Then for example the modulated oscillator 24 may be operated at 30,000 kilocycles while the oscillating detector 28 may be adjusted to a frequency of 30,530 kilocycles, then by means of. the usual heterodyne action the output or anode circuit of the'oscillator detector 28 willhave impressed upon it a frequency of 530 kilocycles which we have'assumed to be the response frequenc of the receiver 17. The numerical values ta en are purely illustrative. It will be readily seen that almost any values if they are properly correlated, may be used.

If a frequency changer of the type schematically illustrated in Fig. 4 is used the operation is somewhat different though the results attained are similar. In this case .the oscillator 24 may be adjusted to any desired frequency and the circuit of the regenerative detector 30 adjusted for maximum sensitivity for the same frequency. The output of the detector 30 modulates in any suitable manner the oscillator 31, The frequency of the modulated output of theoscillator 31 may be permanently set or adjusted by the adjustable condenser 32 to whatever maximum response fr uency is chosen for the receiver 17 e receiver 17 ma have in its output circuitany suitable in icating device such as the loud speaker 18. In summation the invention consists in selecting and amplifying the desired signal at the control unit and modulating and retransmitting at a fixed frequency the modulations of the desired signal at any chosen frequency regardless of the frequency of the incoming wave, retransmitting from the control unit to a frequency changer associated .with any desired receiver, said frequency changer changing the carrier frequency of transfer to the chosen resonant frequency of said re- .ceiver.

It should be understood that the apparatus may be sold complete or the control unit and frequency changer may be sold to beused with i an ordina receiver. A single control unit may be use to excite a number of receivers or a single receiver might be capable of being excited by a number of control units. The cont'rol'unit being relatively small is readily portable and the remainder of the system which may be quite large and cumbersome may be concealed in a closet or other out of the way place. Ordinarily, of course, the loud i tion of a remote contro switch'at or near the lou means connected with sa1 speaker would be located at or near the place where its output is desired and usually near the control unit. Th

e receiver may be turned on and off by a switch operator 33 or by a speaker as in our ap l1cat1on #198,470, filed June 13, 1927.

t will be understood that the control unit will r uire only a small amount of anode and cat ode power and may be energized by small self-contained dry batteries. The frequenc changer and the receiver may be operate by the usual dry cells, storage batteries, or house current, etc. H

We do not wish to limit ourselves to the exact embodiments described except in so far as we are limited in the following claims.

e claim:

1. In a radio receivin system the combine 0 station having a receiving member and; a radiating member, d receiving member lected sigrnal, together with a radio receiver of fixed equency response located at a short distance from the control station and having means for amplification and detection anda frequency converter connected with the ra- Idio receiver having pick-ufp means for receivmg the signals 'radlated r the control station and converting them to the response frequency of the receiver.

2. In a radio receiving system the combina tion of a portable contro station, having a receiving member, means connected with said receiving member for selectin and amplifying the desired signal, an oscillator of fixed frequency'and means for modulating said oscillator in accordance with the modulation of said selected signal, together with a radio receiver of fixed frequency response and located at a short distance from the control station and having means for amplification and detection, a frequency converter connected with said latter means whose output frequency is adjusted to the resonant frequency frequency .converter and means at the 'port- 1 able contrdl station for controlling the volume of the output of the receiver.

3. In a radio receiving system the combination of a control station having a receiving antenna, a radiating member, vacuum tube means connected with said receiving member for selecting and amplifying the desired signal, a vacuum tube oscillator of fixed frequency cGnnected' with said radiating member, means for modulating said oscillator in accordance with the modulation of said selected signal, a source of power for the control station together with a vacuum tube radio receiver at a short distance-from the control station .having vacuum tube means for amplification and detection and a frequency converter connected with said latter means whose output frequency is adjusted to the resonant frequency of said receiver and also modulated by said oscillator and a separate source of power for said receiver.

4. The method of household broadcast reception which comprises collecting and selecting signals of a desired frequency within a broadcast range of frequencies, demodulating the selected signals and amplifying the same, generating a fixed frequency carrier wave and modulating the carrier wave by the amplified 'signals,,radiating the modulated-carrier wave, absorbing and selecting the radiated wave at a distance, demodulating the absorbed and selected wave, enerating a local fixed frequency wave, mo ulating said local fixed frequency wave by the demodulated absorbed wave, impressing the modulated output upon an ordinary radio receiver at a frequency outside the broadcast range and controlling the volume of the output b varying the strength of the first de-.

modu ated signal.

' 5. The method of household broadcast reception whichcomprises collecting and selecting signals of a desired frequency, demodulating the selected signals and amplifying the same, generatin y the amplified signals, radiating the modulated carrier wave, absorbing and selecting the radiated wave at a distance, demoulat-' ing the absorbed and selected wave, generat ing a local fixed'frequency wave, modulating said local fixed frequency wave by the de- 20 modulated absorbed wave, impressing the modulated output upon a radio receiver having radio and audio amplifying stages and controlling the volume of the output by varying the strength of the first demodulatedsignal. t

6. The method of household broadcast reception which comprises collecting and selectinfi signals of a desired frequency within a broadcast range of frequencies, demodulating the selectiadsignals and amplifying the same, generating a fixed frequency carrier wave and modulating the carrier wave by the amplified signals, radiating the modulated carrier wave, absorbing and selecting the radiated wave at a distance, demodulating the absorbed and selected wave, generating a local fixedfrequency wave, modulating said local fixed frequency wave by thedemodulated absorbed wave and impressing the modulated output upon an ordinary radio receiver at avfrequenoy outside the broadcast range; a

' BOWDEN WASHINGTON.

WILSONAULL', JR.

a fixed frequency carrier 1 wave and modu atlng the carrier wave 

